The reaction of aminopropyl trialkoxysilanes with alkyl isothiocyanates is known from A. Baigozhin, Zh. Obshch. Khim. 43 (1973), p. 1408 (C.A. 79: 66463r), which results in N, N'-disubstituted thioureas of the formula (RO).sub.3 Si--(CH.sub.2).sub.3 --NH--CS--NH--R', in which
R=ethyl and
R'=phenyl, allyl.
A symmetric N, N'-substituted compound is described by M. G. Voronkov et al. in Zh. Obshch. Khim. 54 (1984), p. 1098 (C.A. 101: 192031j).
It is obtained by means of the reaction of aminopropyl trialkoxysilanes with thiourea EQU ((RO).sub.3 Si--(CH.sub.2).sub.3 --NH--CS--NH--(CH.sub.2).sub.3 --Si(OR).sub.3).